1. Field of the Invention
The present invention relates, generally, to testing apparatus and methods. More particularly, the invention relates to electromechanical testing apparatus for measuring the spring rate of automobile or kart tires.
2. Background Information
Balancing a car optimizes performance, particularly the cornering characteristics of a racing class automobile. The traction, adherence or grip between the tires and the track at each end of a car is proportional to the percentage of the weight at that end of the car. A car's grip is optimized when both the front tires and the rear tires begin to slide at the same time and at the same rate, resulting in the car having responsive, near-neutral handling characteristics. However, if the front tires slide first, the car tends to understeer and slide off of the track, and if the rear tires slide first, the car tends to oversteer and spin.
Numerous factors contribute to the near-neutral handling characteristics of a balanced car, including tires, wheel alignment, suspension, weight distribution, center of gravity and aerodynamics. A properly suspended car has more braking and acceleration control when the car is moving in a straight line and more steering control when the car is maneuvering around corners.
The spring rate of tires produced with current manufacturing practices vary considerably. For example, a tire produced earlier in the day using a particular tire molding machine will have considerably different characteristics than a tire produced later in the day using the same machine. Additionally, different portions of the same tire may have different characteristics. For example, a particular tire may have soft spots. It is therefore desirable to be able to accurately rate the tires, including the different portions of the tires, in order to balance the car and ultimately improve the handling characteristics of the car.
Applicant's invention provides an apparatus and method for testing and measuring the spring rate of tires which is believed to constitute an improvement over existing technology.